95 replies to this topic

[MrsM75]

I want this one Sir, it says Long Perng 1.25" 55º Long Eye Relief Eyepiece - 6mm

When I look at the specs it says 7 lens in 4 groups, sure this can't be a Plossls

 

Just curious, do you see this eyepiece is more better than the Vixen Lanthanium 6mm, both are 20mm eye relief, so it will come down to the sharpness. I think the Vixen might win.

Edited by MrsM75, 14 April 2025 - 03:41 AM.

[Starman1]

I want this one Sir, it says Long Perng 1.25" 55º Long Eye Relief Eyepiece - 6mm
When I look at the specs it says 7 lens in 4 groups, sure this can't be a Plossls

Just curious, do you see this eyepiece is more better than the Vixen Lanthanium 6mm, both are 20mm eye relief, so it will come down to the sharpness. I think the Vixen might win.

As I said, that LER series is not of Plossl design.
I know it doesn't matter much to you, but the Long Perng eyepieces are better corrected in the outer field, AND the field is a bit wider.
It's also a little better in its mechanical design.

[MrsM75]

Sir Starman,

 

is the old Zhumell Z Series 1.25 eyepiece good Sir?

[Starman1]

Sir Starman,

is the old Zhumell Z Series 1.25 eyepiece good Sir?

I think that is the same as the Long Perng LER.

[MrsM75]

Thank you Sir.

 

It does seem the same, it looks exactly alike beside the name on it.

 

I just got one for $40 (the Zhumell) half the price of the Long Perng one which is like $89

 

I hope it looks the same, visually wise. The Zhumell seem to be very old series, it like discontinue now.

[MrsM75]

Sir I have a question, the Astromania 58 degree UWA Planetary eyepiece it just the BST 58 degrees UWA eyepiece. I'm guessing they the same. The Astromania price is cheaper than the BST one, it is good Sir? I was thinking of try one.

[Oldfracguy]

Sir I have a question, the Astromania 58 degree UWA Planetary eyepiece it just the BST 58 degrees UWA eyepiece. I'm guessing they the same. The Astromania price is cheaper than the BST one, it is good Sir? I was thinking of try one.

MrsM75...please let me chime in here.  I used those BST 58° Planetary eyepieces for at least three years.  I had the 2.5, 4, 5, 6, 7 and 8mm models over that time:

 

 

They have rotatable eye cups just like the Dual ED StarGuider/AT Paradigms and the Tele Vue DeLites:

 

 

 

so you can adjust the eye cup to wherever you like it best:

 

 

 

They are quite good.  I started selling off mine when I got some Nagler Type 6 and DeLites.  I have never tried the longer focal length BST 58° Planetary eyepieces like what you might need with your f/12.75 and f/15 Maks, but the ones I had did a very nice job.  I sometimes saw a little internal reflection, but not all the time.

Edited by Oldfracguy, 16 April 2025 - 10:05 PM.

[MrsM75]

MrsM75...please let me chime in here.  I used those BST 58° Planetary eyepieces for at least three years.  I had the 2.5, 4, 5, 6, 7 and 8mm models over that time:

 

 

 

They are quite good.  I started selling off mine when I got some Nagler Type 6 and DeLites.  I have never tried the longer focal length BST 58° Planetary eyepieces like what you might need with your f/12.75 and f/15 Maks, but the ones I had did a very nice job.  I sometimes saw a little internal reflection, but not all the time.

 

aaaaa thank you so much Sir Oldfracguy. I can get this for $40 on Amazon (15% coupon off) under the brand Astromania, I just want the 7mm for planetary in my Mak.

 

Thank you for your review, I be buy one. I do not have money for Televue Delite, so this is my alternative.

 

'

Edited by MrsM75, 17 April 2025 - 12:22 AM.

[WADAM12]

Amazon it is $266 for the 1.25 ones Pantex. 10mm 7mm 14mm 20mm

The 2 inches Pantex one is $450  16.5mm and 23mm

 

The price is expensive, I think I have no choice but pass.

 

I was wondering if the Long Perng 1.25" 55º is good, it alot cheaper.

In Poland, the Pentax XW 23 and 16.5 costs $665

[MrsM75]

Sir Starman1, is this BST  58-deg UWA Planetary eyepiece, good Sir? I need one magnification from that, I heard bad reviews about it.

[Starman1]

Sir Starman1, is this BST  58-deg UWA Planetary eyepiece, good Sir? I need one magnification from that, I heard bad reviews about it.

The quality varies according to the focal length, even in long f/ratio scopes like yours.

I cannot tell you which focal lengths are good and which aren't.

General reviews say the Celestron X-Cel LX and Astrotech Paradigm/BST Starguider ED are better eyepieces, however.

[MrsM75]

Thank you Sir. I have a question.

 

Is the Apertura Plossl good? I mean Plossl is Plossl, but hear me out. 

 

Example, the Vixen NPL Plossl the 20mm eyepiece it 15mm eye relief.

But the Apertura Plossl same 20mm eyepiece but it has 20mm eye relief.

 

I think of try one, or is High Point Scientific give a wrong eye relief here? 

Edited by MrsM75, 26 April 2025 - 01:36 AM.

[Starman1]

Thank you Sir. I have a question.

 

Is the Apertura Plossl good? I mean Plossl is Plossl, but hear me out. 

 

Example, the Vixen NPL Plossl the 20mm eyepiece it 15mm eye relief.

But the Apertura Plossl same 20mm eyepiece but it has 20mm eye relief.

 

I think of try one, or is High Point Scientific give a wrong eye relief here? 

Here are some facts:

1) The Apertura Plössl is a GSO Plössl under the private label of High Point Scientific.  GSO Plössls are available many places.

2) Modern Plössls have an eye relief that is about 0.7 x the focal length, so a 20mm Plössl, no matter who it's from, will have about a 14mm eye relief +/- 0.5mm.

So the 20mm claim on the Apertura Plössl is wrong.  It is likely copied over from a longer focal length when their web pages were created.  This happens all the time.

3) If you prefer a longer eye relief, then Plössls are not the eyepieces you want if they are shorter than 25mm.

 

There are many inexpensive eyepieces with longer eye reliefs.  For example, Celestron X-Cel LX.

Another example: Sky Rover Premium Flat Field eyepieces that are sold in 3.5mm, 5.5mm, 7.5mm, 10.5mm, 15.5mm, 19mm, and 25mm on AliExpress (shipped directly from China)

Some of the focal lengths are sold my Astronomics, the sponsor of CloudyNights, as Astrotech PF eyepieces.  Sky Rover is the manufacturer's 'house brand' name.

They would work well in your long focal ratio scopes.

[MrsM75]

Sir Starman1, one more question Sir, Sir, is the Pentax XF smc which say it for Spotting scope. But would it work with a Mak? Or it just strictly Spotting scope only?

 

Thank you Sir.

[Starman1]

Sir Starman1, one more question Sir, Sir, is the Pentax XF smc which say it for Spotting scope. But would it work with a Mak? Or it just strictly Spotting scope only?

Thank you Sir.

The Pentax XF Zoom is poor quality, but the two XF fixed focus are decent eyepieces.
They are sharp enough, but suffer from scattered internal light on bright objects. Comparisons with the Astrotech Paradigms show the Paradigms to be a little better in that regard.
They would, like nearly all 1.25" eyepieces, work fine in your scopes.

Edited by Starman1, 01 May 2025 - 12:33 AM.

[MrsM75]

Sir Starman1, I have a question. I was reading an old thread here on CN, it say the Zhumell Z eyepiece series 55 deg, which is same as the Long Pergn 55 deg

It say the Zhumell Z series got discontinued because it contain Lead glass, while the Long Pergn does not. Is this true? Because I have a Zhumell Z eyepiece 55 deg, I actually like it very much, but does it contain Lead glass?

[Starman1]

It might contain lead glass.

To protect yourself, don't grind it up and eat it.

Otherwise, there is zero threat from having glass with a lead content.

The Zhumell Z series was dropped by Hayneedle when their telescope division shut down.

[MrsM75]

Thank you Sir. Sorry one more question Sir.

 

You know the Celestron Omni 32mm Plossl ep, it say the actual degree is 44 degree (instead of 50 deg like advertise)

 

So does that means the Vixen NPL 30mm Plossl is also 44 deg too instead of 50 deg like Vixen advertise their Plossl?

 

And yep, I thought so too I am not licking the lens glass nor drink out of it, I am basically put my eyes near it to see through it, so the Lead glass should be okay, I actually like the eyepiece and not want to throw it away, I was able to get it $40 New Zhumell 18mm

Edited by MrsM75, 02 May 2025 - 12:09 AM.

[Starman1]

32mm Plössls vary from 43-49° depending on the field stop and the distortion characteristics.

Examples:

Baader--45°

Meade--46.3°

Tele Vue--49°

Vixen--47.5°

Orion Sirius--44°

If you read the ads for these, they are all 50° or 52° (to their credit, Baader does say 45°).

In reality, they are not.

Is the Omni actually 44°?  Possibly.  I've not seen a test done on that one.

I remember one line of Plössls advertised as 52° an called "Super Plössls".  They varied from 47-51.8°, but only 2 focal lengths in the 9 focal length line were larger than 50°.

 

Advertising isn't always accurate where apparent fields are concerned.

They know no one is going to measure the actual apparent fields on a $50 eyepiece.

 

What happens is that when a website is having a group of eyepieces added, the web poster often just copies the information from one focal length to another without being aware that

the information for 32mm and 40mm Plössls is different than the shorter focal lengths.  40mm Plössls vary from 37-43°, yet many are advertised as being 50°, which isn't even possible.

[Oldfracguy]

At some point with these long focal length 1.25" Plossls or other type of eyepiece you will get to where the Field Stops are about 28 mm, the inside diameter of a typical 1.25" eyepiece barrel.  It makes no difference after that what the particular eyepiece's AFOV value may or may not be as it appears in the specs.

 

Download and read Starman1's eyepiece Excel Spreadsheet and concentrate of the size of the Field Stop.  When it gets close to 28 mm the maximum True Field of View (TFOV) you are going to get will be very close to (57.3 x 28) / (Your Telescope's Focal Length in millimeters).

 

Example:  Skymax 102..1,300 mm Focal Length...max TFOV with any 1.25" eyepiece is (57.3 x 28) / (1,300)  =  1.23°

[MrsM75]

Hi Sir, what you think of the Badder Hyperion, the 8 lens elements 5 groups. Weight 16 oz which is 1 lb

 

I think it heavy for my small Maks, because last time the Luminos which also weight 1 lb, it literally tilt my Mak and also vibrating when look in due to it just heavy for my 1.25 diagonal.

 

The Hyerpion seem like it even heavier due to it 8 lens elements in there. 

 

I think of try one, the Hyperion, because I can get one now 20% off, for $150 instead of $196

[Starman1]

Hyperions would work well in your Maks, but if the Luminos caused imbalance, so will the Hyperions.

[MrsM75]

Hyperions would work well in your Maks, but if the Luminos caused imbalance, so will the Hyperions.

 

Sir, can I say my setup so you can see what can cause the imbalance. So I was using my 90mm Skymax Mak which weight 3.5 lbs

And I use the GSO dielectric diagonal.

And the Luminos weight 1 lb

I thought 1 lb eyepiece it would be okay due to my Mak it 3.5 lbs

 

Nope, it literally tilt my Mak,I mean it tilt to the direction of the diagonal where I have the eyepiece in there, and what worst is it cause VIBRATING when I look inside the eyepiece, the image vibrate.

 

Something is wrong here, so I am guessing a 3.5 lbs Mak cannot take a 1 lb eyepiece weight.

[MrsM75]

The 1 lb weight Luminos which I returned due to the moldy box, that eyepiece vibrate due to the heavy weight. 

But then when I buy the clone Astromania 82 deg, it same lens it just different housing, and it weight only half a pound, and it no longer vibrate.

So I don't think my 3.5 lbs Mak can take a 1 lb eyepiece weight.

 

eta: Never mind, Hyperion it no longer on sale 20% off, it is back to $196 price which is $200 price now. So I won't buy it, it out of my budget.

Edited by MrsM75, 04 May 2025 - 09:00 PM.

[MrsM75]

Sir Starman1, I need your help Sir.

 

So I got these cheap eyepiece for $40, I bought two, it the Zhumell/Long Pergn 55 deg. Please look at the coating inside the barrel (I shine the light in so you can see what I mean), the eyepiece on the right it sand black there no shinny. The eyepiece on the left it still black but it was not sand (like no coating over) so it shinny.

 

I do not know if these two eyepieces from two different batches, and they just use different type of coating. But the right eyepiece eventhough it black color like the left, but it shinny. I worry it will give me glare when I view bright object. I plan to return the left eyepiece.

 

What you think Sir, they forget to paint the coating, or it just shinny coating, instead of the sand like not shinny coating. I can take another pic if you want, but I think you can see what I mean.